It is known for many decades to deploy loads out of an aircraft by means of an aerial delivery parachute in military operations and disaster relief situations. Basically, there are three different methods for delivering the loads. In one method a parachute may be deployed into the surrounding airflow of the aircraft, which parachute is attached to the load to be delivered. Hence, a traction force acts on the load, which is held by air delivery locks in place. When reaching a predetermined traction force, the air delivery locks are released and the cargo is pulled out of the aircraft by means of the parachute. Another common method for deploying cargo from an aircraft is conducted by increasing the angle of attack of the aircraft, such that the cargo load is dropped out gravity-driven. In doing so, the parachute will be deployed after the drop. A third method is known as combat offloading. Here, the aircraft is flying at a very low altitude above the cargo deployment area or it may even touch down in the fashion of a touch and go landing. Subsequently the aircraft accelerates, and the cargo is deployed by the inertia loads due to the acceleration. With this method no drop parachute is used, but a small extraction parachute may be an option.
The air delivery locks used for holding the cargo in place are commonly automatic locks. The locks are responsible for restraining the cargo in an X-direction, i.e. in a forward/rearward direction, and are mounted to guiding rails that restrict the pallet movement in a Z-direction, i.e. vertical, as well as in an Y-direction, i.e. lateral. The guide rails and the delivery locks are located underneath a cargo floor and can be folded up. The cargo pallet to be deployed rests against the restraining device and exerts a certain force onto the restraining device through a mechanical link including a spring. Upon reaching a predetermined pressing force of the cargo pallet, the pallets are released. Hence, when a deployment parachute pulls the cargo, it is automatically released once a predetermined force is reached or exceeded.